Cure Characteristics and Thermal Properties of Sulfur-Cured EPDM-Based Composites by Compounding with Layered Nano-Organoclays

摘要

Organoclay was compounded with ethylene-propylene-diene-monomer (EPDM) using a two roll mill and cured by conventional sulfur curing system.The organoclay content was progressively increased from 0 to 10 parts per hundred of rubber (phr) of the EPDM rubber.Cure characteristics were carried out on an Ekktron moving die rheometer.It has been found that cure and scorch time were decreased with organoclay loading.On the other hand,minimum and maximum torque has been increased with organoclay loading as well.The observed trend was related mainly to the strong interaction between the rubber matrix and the nanoscaled filler (organoclay in this case) and subsequently to the improved crosslink density.Such improvement was attributed to the small size of the filler particles and to the amine functionality in the organoclay structure.Thermal analysis obtained from differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed that,the enthalpy of vulcanization increased with organoclay content indicating increased cross-link density formation,whereas TGA analysis showed that organoclay has increased the thermal stability of the EPDM hybrids.